The Mosul district of Gogjali was captured from the Islamic State group weeks ago. So the commander of Iraqi troops here was alarmed when a surprise attack by militants sparked an hour-long gunbattle with his forces.

None of his men were hurt, but the assault meant IS sleeper cells remained among the mainly Sunni Muslim population.

Using loudspeakers, troops on Thursday called on all adult men to report to the main square. About 400 showed up. Under heavy guard and forbidden from using cell phones, they sat on the ground — clearly anxious they were about to face mass reprisals.

Instead, the commander delivered a speech, demanding information but also seeking reconciliation.

"I am a Shiite, but it's not true what you hear that we are here to fight Sunnis," Col. Munir Abdul-Aziz, a burly man in his 40s, told them. "We are here to save you from the terrorist Daesh which has no religion," he added, using the Arabic acronym for IS.

It was a sign of how, in the campaign to retake Mosul, Iraq's military and politicians are making a concerted effort to bridge the country's bitter Sunni-Shiite divide.

The Iraqi army is opening up a new front to the northwest of Mosul in order to lay siege to the western part of the city where ISIL are holding out. The narrow winding streets of the Old City greatly favor the defenders.